The injured officer is said to be "recovering well in hospital" but faces further surgery.

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The aftermath of the shooting - an armed police officer is distinguishable in the lower right-hand corner of this picture

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The shooting happened near a petrol station on the Crumlin Road

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Bullet holes in the windows of the filling station

The chief constable said people were filling their cars with fuel at the garage when the shots were fired and there were "multiple strike marks on the forecourt".

'Just crazy'

He added that police now believe the attack was not a drive-by shooting but that a gunman fired shots from behind a fence, across the road from the petrol station.

"This is an attack on the entire community, people walking from the forecourt to their cars with bullets whizzing round them and striking the garage forecourt - completely reckless," he said.

"Whatever people's motivation for doing this, it is just crazy."

He added that the officer was "wearing ballistic body armour which may have helped".

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Media captionAn eyewitness spoke to BBC News NI's Sara Neill

Mr Hamilton said such incidents "don't happen on ad hoc or opportunistic way. So we'd be pretty convinced that this is a planned operation"

The chief constable added: "The use of violence for any sort of political objective hasn't worked in the past and it's certainly not going to work in the future."

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Police said people were filling their cars with petrol to find "bullets whizzing around them"

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Forensic officers were at the scene on Monday

The PSNI detective leading the investigation, Det Supt Kevin Geddes, said: "We have recovered bullets from a number of locations on the forecourt and in several cars."

He added that his officers were trying to trace the movements of a red Audi A4, registration number KNZ 2862.

He appealed for sightings of the getaway car on Flax Street and Crumlin Road at about 19:30 GMT on Sunday.

It was found burnt out in Culmore Gardens about 30 minutes later.

"I'd also like to hear from anyone who noticed this car and its movements during December 2016 up to last night's shooting," Mr Geddis added.

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The scene remained closed on Monday morning

Northern Ireland Secretary James Brokenshire and the NI Justice Minister Claire Sugden have described the attack as "sickening".

Ms Sugden said there remained a significant terrorist threat in Northern Ireland "particularly against PSNI officers and indeed prison officers and that threat hasn't gone away with political instability, if anything it has been heightened.

"I had voiced my concerns at the outset of all the political instability that we need to be vigilant against this type of attack because I do think there will be people who will take that opportunity."

Assistant Chief Constable Mark Hamilton said the attack was "reckless madness" and warned that there could have been "multiple deaths".

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Media captionPolice have said the shooting of a police officer in north Belfast was 'reckless madness'.

"This was a very concerted attack on our officers - a very concerted attempt to murder them," he added.

Mark Lindsay, chairman of the Police Federation for Northern Ireland, said it was "an appalling act".

"This attack on the life of an officer is a stark reminder of the determination on the part of terrorists to murder and maim police officers," he said.

"They believe that by causing great grief to a family they are somehow advancing their warped and outdated plan. The wider community will be outraged by this attack on one of their police officers.

'Deeply disturbing'

"This attempted murder underlines the fragility of our peace."

DUP leader Arlene Foster condemned the shooting and said it was "the work of cowards".

Sinn Féin's Gerry Kelly said those responsible had "absolutely nothing to offer society and need to call a halt to these activities immediately".

The Social Democratic and Labour Party's Nichola Mallon said those involved in the attack were "calculating criminals intent on destabilising a community which continues to make strides toward reconciliation".

Alliance Leader Naomi Long said she believed they "intended to kill" and that "using guns in a residential area shows a callous disregard for the entire community".

Ulster Unionist leader Mike Nesbitt said: "We must find a way to end this."

The leader of the Traditional Unionist Voice (TUV), Jim Allister, said the incident was a "reminder of the wickedness and criminality of all terrorism".